TotalBoat Silica Thickener (Cabosil)

TotalBoat Silica Thickener is an extremely fine high density epoxy filler that mixes to a smooth, non-sagging and easy to sand solution. Often used to control the viscosity of epoxy and commonly used on structural bonding, filling and filleting applications.

Material is also called colloidal or fumed silica, as well as cabosil, and can be mixed with epoxy on its own or added into a blend of epoxy fillers if necessary.

2013-10-23RICHARD HONAN asked:What does the one quart container of Cab-O Sil thickener weight?

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2013-10-23DAVID MEDEIROS:Almost nothing. Probably less than the container.

2013-10-23Richard Honan:Hello David, I know it doesn't weigh much. I only wanted to know the weight when compared to West System silica. West is selling it by weight and Jamestown is selling it by volume. They sell their silica in a 5.5 oz container. In order to compare prices, I wanted to know what a quart weighs.

2013-10-23DAVID MEDEIROS:You're talking to the wrong person if you are choosing based on price. I think that whatever the difference is, it's not worth the time you have already spent researching it. I thought the Cab-O Sil was easier to work with, and since it's what people I know who do this stuff for a living recommended, that was all I needed.

2013-10-23CHRIS FAUVEL:I don't actually know the weight , but can tell you it is next to nothing. The weight is from the container not the product. You almost feel jipped, because it feels so light.
You are paying for the volume not the weight.

2013-10-23Richard Honan:Hello Chris, I know it doesn't weigh much. I only wanted to know the weight when compared to West System silica. West is selling it by weight and Jamestown is selling it by volume. They sell their silica in a 5.5 oz container. In order to compare prices, I wanted to know what a quart weighs.

2013-07-23A shopper asked:what is ratio to epoxy recomended?

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2013-07-23ROBERT MCGAHA:I don't think there is a standard ratio for mixing. The purpose for adding Cab-o-sil is to thicken your epoxy so that it doesn't run out of a joint or run off the surface you're applying it to. I just add it to the epoxy in small amounts until it reaches the viscosity I want.

2013-07-24DANIEL BLANK:I have been using this product on my boat for the last two years. From experience and everything that I have read, there is no set ratio for how much silica to use. For me, I just put how every much was needed for the epoxy to hold firm when applying to vertical surfaces. The silica does not really diminish the strength of the epoxy. Just start with a small amount and keep adding more and more until you are satisfied with the thickness.

2013-07-24JOHN BECK:Since this stuff is so light (it is so light you might think they sold you and empty container) all you can do is add a little at a time, mix it, judge if you have the correct thickness (from syrup to peanut butter) and add more as needed. For an epoxy volume created with one mini-pump shot I'd start with about 1 shotglass volume of filler and go from there. A quart of cabosil would be enough for at least a half gallon of epoxy, more or less depending on how thick you need it.

2013-07-29DAVID MEDEIROS:There was no ratio targeted. Just add the thickener to the epoxy until the pastiness or consistency you are looking for is reached. Obviously it will vary per application. If you are unsure of how much to thicken the epoxy, work with a small amount and glue some scrap material.

2012-02-06STEPHEN RICHMAN:I have not used the Cabosil product but have used both the Jamestown and MAS fused silica and found them to be virtually the same.

2012-01-16A shopper asked:Is this product toxic in itself?

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2012-01-17DANIEL CAOUETTE:No but...
The product is fumed silica, the main component of glass. In other words: it's very, very fine glass. It has particle size of 5â??50 nm. Fumed silica is not listed as a carcinogen by OSHA, IARC, or NTP. Due to its fineness and thinness, fumed silica can easily become airborne, making it an inhalation risk, capable of causing irritation. Wear a dust mask.

2012-01-17BRIAN CURTISS:The MSDS sheet has rated this materials HEALTH at 1, witch means, a slight hazard- irritation or minor reversible injury is possible.
It should be treated as a nuance dust.

2012-01-17WILLIAM BROADLEY:always wear a mask....

2012-01-17KARL NISSON:The best answer to this question is:
GOOGLE Cab-o-sil MSDS. (Material Safety Data Sheet)
If you have a question about any product the MSDS will answer your question.

2012-01-18DALE QUAKENBUSH:I don't think so. It is very fine and floats in the air so I wera a dust mask.

2012-01-18TERRY DUVIEILH:I have used the product a few times for thickening epoxy and polyester resins and have not had any problems with skin or eye irritation when handling it. In its raw state, its very light and fluffy. It will get into the air and generate a lot of dust when you are mixing or otherwise handling it. As always, use protective gear. A quick web-search will find MSDS sheets and other data for almost any material. This material appears to be widely used in consumer products like shampoo, soaps, and even medications so it would seem to be non-toxic.

2012-01-06NORMA JEAN DAVIS asked:hi my name is Norma i was wondering if this could be used to fix cracked plastic in the top of a radiator of a car ?

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2012-01-06CHRIS CRANDALL:No, no, a thousand times, no. Your real issue is what resin/glue? But frankly, a trip to the junkyard should be in your future.

2011-09-21PAUL MASCARO asked:can this product be used by itself.
?

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2011-09-21LARRY BLACK:I've had good luck mixing it as a strengthener and thickener with Mas Epoxy. It does not cure clear but a little bit white. There need be no other additive.

2011-09-21ROBERT MCGAHA:Paul, I'm assuming by your question you mean "can I add it to the fiberglass resin by itself?" and the answer is yes. You do not necessarily have to add any additional fiber filler or chopped glass ect. to your resin to use this thickener. I have used it with and without additional fillers. depending on what the objective was. The main reason I use Silica Cab-o-sil Thickener is in basically when glueing surfaces together so that the resin doesn't run out of the joint or if I'm fiberglassing something whether flat or on a slope to help minimize the resin from running. My experiance has also been that when using thickener that your work time shortens.

2011-09-21CHRIS CRANDALL:Can't imagine why. Its primary purpose is to thicken another liquid or gel (or to turn a liquid into a gel). If used "by itself" it will just blow away.

2011-09-21SETH WOOD:If you mean: can it be added to epoxy as the only thickener, then yes. It creates a very strong and tough adhesive, much stronger than just the resin/hardener mix, which should not be used as adhesive unless you add something to it. Like this silica powder.

2011-09-21JOHN LAUPHEIMER:Silica Cab-o-sil Thickener is used to thicken epoxy to give it thixotropic properties (meaning it stays where you put it) and to make the epoxy gap filling. It is mixed into any of the major manufacturers generic epoxy to create a glue or a fillet paste. You use less for a glue and more for fillets. The epoxy is mixed first according to the manufacturer's instructions. Often the surfaces are wetted out with this relatively thin liquid and then the silica is added to the pot of mixed epoxy. This is then spread on one surface or into the fillet area.. The stuff is bad for your lungs so wear a respirator or a dust mask.

2011-09-21KEVIN MATKOSKI:By itself? No. It is a poweder of very fine glass particles. It could almost be classified as a dust. Don't use it in an open environment where ther is a breeze.
If you mean, can be used as the only additive to your epoxy mix... then yes. I start with a tablespoon of Cab-o-sil per pump of resin. This way you can keep it ready for use. Then add hardener. If it's too thin, just add more cab-o-sil.
As a side note, I have not had any problems using just cab-o-sil, but the dried resin is very hard. I add some microbaloons to make it more sandable.

2011-09-21BARRY CUNNINGHAM:If you mean can it be used alone to thicken your epoxy, absolutely. Here's what i've learned working with this product: 1) mix your resin and hardener thourghly first 2) careful where you pour in the silica - it's very light so if there's any wind it'll fly all over. Not good stuff to be breathing either 3) it's as hard (or harder) to sand than the epoxy when it's cured. If you are using it to fair, better to take a look at the micro ballon fillers made for sanding.
It leaves the epoxy milky when it cures, but it's a great solution for all sorts of structural type aplications. I've mixed it as thick as peanut butter and filled joints overhead with success - good luck!

2011-09-21THOMAS RITZLER:no... this product is meant to be used with an epoxy product as a thickener
to add viscosity and strength to your project
its liek super fine ground consistency
and your should always wear a mask and in low wind conditions
don't ask me how i know that :)
hope this helps

2011-09-21JACK HOBSON-DUPONT:Maybe I misunderstand your question. How would you use Cab-O-Sil by itself? It's an extremely light, flaky, powdery substance that would just blow away by itself. It needs to be added to a liquid, to make the liquid more viscous.

2011-09-21TED DWYER:I have used this product many times to thicken MAS epoxy. It does a great job of allowing me to fill voids and create smooth fillets with no mess and no drips. It is EXTREMELY fine powder. I would not go near an open container of it without a mask, the smallest breeze will send it into the air.

This product is great at doing all of the things it says. I find that the west system 404 filler is more dense and better for structural applications, but I add this filler to my 404 at the end of my mixing. I find that it gives the 404 a better thickness, reducing the sag, and making spreading much easier. Add a little at a time to get used how fast it gives the desired consistency. I do this same thing with microlight and other fairing compounds for the same reason, just use sparingly with fairing compounds as it can become more difficult to sand. Bottom line, great filler by itself, but is very effective when added top other fillers to get that just right consistency.

I purchased this product to thicken epoxy for gluing wood together. I am building a Guideboat and many joints are vertical, this product does well to thicken the epoxy and keep it from running. It is very light and fluffy, so when scooping it out of the container it is likely you will loose some as it 'poofs' out.